Cultivation Base of State Key Laboratory for Ecological Restoration and Ecosystem Management of Jilin Province and Ministry of Science and Technology, College of Chinese Medicinal Materials, Jilin Agricultural University, Changchun, 130118, Jilin, People's Republic of China.
Planta. 2021 Mar 19;253(4):79. doi: 10.1007/s00425-020-03535-7.
Short-term cold stress can induce the increased expression of key enzyme-encoding genes involved in secondary metabolite synthesis, thereby increasing secondary metabolite concentration. Cold stress is an ecologically limiting factor that strongly affects the physiological and biochemical properties of medicinal plants often resulting in changes of the secondary metabolic process. Ginsenosides are the main active ingredients in medicinal ginseng yet few studies exist on the effect of cold stress on the expression of ginsenosides or the molecular mechanism underlying its regulation. Here, we evaluated the effects of cold stress on the physiological characteristics and secondary metabolism of P. ginseng embryogenic calli. Physiological measurements and RNA-Seq analysis were used to dissect the metabolic and molecular responses of P. ginseng to cold conditions. We found that the dynamic accumulation of ginsenoside and various physiological indicators leads to homogenous adaptation to cold stress. Secondary metabolism of ginseng could be a compensation mechanism to facilitate its adaptation to cold stress. Combined with the changes in the endogenous hormone content, 9-cis-epoxycarotenoid dioxygenase (NCED), zeaxanthin epoxidase (ZEP), and short chain dehydrogenase (SDR) from the abscisic acid (ABA) synthesis pathway were identified as key mediators of this response. Thus, an appropriate degree of cold stress may promote accumulation of ginsenosides. Moreover, 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR2), squalene epoxidase (SE1), squalene synthase (SS), dammarenediol synthase (DS-II), and β-alanine C-28 hydroxylase (CYP716A52v2) should be considered key mediators of the cold stress response and ginsenoside biosynthesis. During industrial production, short-term cold stress should be carried out on ginseng calli to improve the quality of its medicinal materials.
短期冷胁迫可诱导参与次生代谢物合成的关键酶编码基因的表达增加，从而提高次生代谢物浓度。冷胁迫是一种生态限制因素，强烈影响药用植物的生理生化特性，常导致次生代谢过程的变化。人参皂苷是药用人参的主要活性成分，但关于冷胁迫对人参皂苷表达的影响及其调控的分子机制的研究甚少。在这里，我们评估了冷胁迫对人参胚性愈伤组织的生理特性和次生代谢的影响。生理测量和 RNA-Seq 分析用于剖析人参对冷条件的代谢和分子反应。我们发现，人参皂苷的动态积累和各种生理指标导致对冷胁迫的均匀适应。人参的次生代谢可能是一种补偿机制，有助于其适应冷胁迫。结合内源激素含量的变化，鉴定出 9-顺式-环氧类胡萝卜素双加氧酶（NCED）、玉米黄质环氧化酶（ZEP）和短链脱氢酶（SDR）是该反应的关键调节因子。因此，适度的冷胁迫可能会促进人参皂苷的积累。此外，3-羟-3-甲基戊二酰辅酶 A 还原酶（HMGR2）、角鲨烯环氧化酶（SE1）、角鲨烯合酶（SS）、达玛烯二醇合酶（DS-II）和β-丙氨酸 C-28 羟化酶（CYP716A52v2）应被视为冷胁迫反应和人参皂苷生物合成的关键调节因子。在工业生产中，应对人参愈伤组织进行短期冷胁迫，以提高其药材质量。
